Elevated white blood cell count and long-term clinical outcomes of patients with vasospastic angina.

Objectives: Inflammation is known as one of key pathophysiologic mechanisms of coronary artery disease. We aimed to investigate the relationship between white blood cell (WBC) count and long-term clinical outcomes of patients with vasospastic angina (VA).

Methods: A total of 823 patients who were diagnosed as VA without significant coronary lesion by coronary angiography with ergonovine provocation test were enrolled for analysis. Patients were divided according to WBC count tertile at the time of diagnosis: group I, tertile 1 and 2 (n = 546, <7490/ml); group II, tertile 3 (n = 277, ≥7490/ml). Primary outcome was defined as major adverse cardiovascular events (MACE), a composite outcome of all-cause death, cardiac death, myocardial infarction (MI), readmission due to cardiac symptoms, and revascularization.

Results: Median follow-up duration was 4.3 years. No significant difference of primary outcome was observed between group I and group II (14.7% vs. 20.2%, hazard ratio (HR) 1.29, confidence interval (CI) 0.90-1.83, P  = 0.162), while incidence of cardiac death and MI was significantly higher in group II (1.5% vs. 4.3%, HR 2.86, CI 1.14-7.17), P  = 0.025). In multivariate Cox regression model, elevated WBC count at the time of diagnosis of VA was an independent predictor of MI (HR 3.43, CI 1.02-11.59, P  = 0.047).

Conclusion: Elevated WBC count at the time of diagnosis was associated with a significantly increased risk of cardiac death and MI during long-term follow-up in VA patients.